Various types of patient transporting vehicles, commonly referred to as mobile stretchers, have heretofore been provided for use in hospitals, clinics, and various other medical facilities for moving a patient from one location to another while the patient is in a prone, reclining, or sitting position. Such vehicles are normally provided with a plurality of wheels, casters or the like, of which one or more is of a swivel type to facilitate steering of the vehicle. The axles of the wheels are oftentimes fixedly secured to the underside of a rigid frame which supports at a predetermined elevation a patient supporting member, sometimes referred to as the litter. In other situations the wheels are disposed in bearings which have external stems or stubs which in turn are disposed within sockets rigidly affixed to the frame underside. In either situation, because of the manner in which the wheels are affixed to the frame, any lateral forces impacting on the wheels due to the latter striking a curb, stanchion, or other floor projection while the vehicle is in motion causes the connection between the wheel and the underside of the frame to be weakened and eventually to fracture or become seriously damaged. In addition, such forces are frequently transmitted through the rigid frame and litter to the patient, causing discomfort and pain to the patient being transported. Thus, in order to withstand the shock forces to which the wheels of the vehicle are frequently subjected and for reasons of safety and stability, it has been customary in prior vehicles of this general type for the frames to be inordinately massive, heavy and rigid structures and accordingly expensive and difficult to manually maneuver, and the wheels, casters, or the like connected thereto to be reinforced.